Multiple-screw jack



with teeth 38 and teeth 4t2 are in mesh. with teeth 32 and the operator reciproca/tes handle 28. in a horizontal plane, motion of this handle in one direction will cause one screw to move in a given longitudinal direction with reference to the case l() and that the reverse movement of the lever 28 will cause the other screw to move in the same direction with reference to the case l0, with the result that reciprocation of handle 28 causes a continuous movement in the given direction of jbloclr 22, that direction of motion de ending upon the way the sets of teeth re erred to are at manufacture pointed.

The problem oi this invention is to provide mechanism which. will convert a jack having the foregoing; parts so that this general direction oli' motion of the lifting block 22 may be reversed at the will of the operator. This may be accomplished by the following mechanism:

- The rider 40 is extended outside of the ring of teeth ft2, heretofore described, and is provided outside said ring of teeth with a second ring of teeth reversed in angular position to the first set of teeth 4:2 Loosely surrounding* the portion 30 of the screw and below these teeth 54 is a ratchet ring 56 having, on its upper circumference, a set of ratchet teeth 58 adapted to interit with the teeth 54 ust described, all as clearly shown in Fig, 7.

At suitable points around the circumfcn ence of the ring 56 are diagonal cam slots 60. 'These slots are entered respectively by Studs or pins 62 supported rigidly on the inside of a cap'or case G4. At other points in the reciprocatable member 56 between the Slots 60 are other vertical slots 66 entered by screw studs 68, shown in Fig. l mounted in the case member 10. These screw studs being stationary on the frame, it is obvious that the ratchet member 5G can move up and down with reference to the case in distagice equal to ldie lengths of the slots 6G and can not move in any other direction with r'e'terence to the jack case. These pinsor studs 68, just referred to, extend out beyond the member 56 into horizontally disposed circumferentialfslots in cover 64. These slots are provided at their ends with locking notches 7 2 in which the pins rest for locking; purposes. From the foregoing, it will be seen that 'when the operator takes hold of cover 64; and gives it a horizontal rotation, the length ot slots 70 he thereby forces studs (32 carried by that cover to travel alongV slots ($0. As cover G4 can only rotate in the plane of slots 7() duc to the guiding action of fixed Studs G8 and, as member 56 is free to recipr0- cate ay distance. equal to slot 60, it is obvious that this rotation of cover 64 forces member 56 to reciprocate a distance equal to the lengiths of slots GG, n., the stud 62 travels theA length ot slot 60. This length ol. vertimessen cal movement of the member 56 is suliicient so that when it is in its estreme elevated p0 sition, it lifts Athe plate l0 to a. suthcient height so that teeth 42 valways clear teeth 32, and that teeth 54 mesh with teeth. 58, and that when .this member is in its extreme lower position teeth ll2 are in mesh with teeth 32, and teeth 58 are so low down that they can nevermesh with teeth 54j The result of this construction is that all the operator `has to do to malte the screw 18 rotate in a direction which he desires, is to select whichever set of teeth 54-58 or 4232 should be in mesh under the original con struction of the jack to effect that rotation.. A substantially similar construction is present in connection with the plate 48, heretofore described. At this point, a ring 72 corresponding to member 56 is provided, there being on the upper edge oi this rin ratchet teeth. 74C ,meshing with teeth 76 on the outer circumference oi' plate a8 extending around the teeth 52, heretofore described and pointed in the opposite direction. The stud 84, heretofore referred to, performs all the functions of stud (i8 in the prior construction traveling in a. slot 7S in the cover corresponding in all the functions to cover 64, heretofore described. This cover, as before, carries studs S2 identical with the stud G2, heretofore described, whichstuds 82 travel in diagonal slots 84 corresponding to slots 60. As before, the studs 32 pass through vertical elongated slots 8G corresponding to slots 66, heretofore described.

The result of thisl construction is that assumingF the jack in collapsed position ol Fig. l and that the operator desires to have each opposite stroke ot' handle 23 effect continuouselevating ot' bloc.k 22, he takes hold ot- `the covers 8() and't4f one after the other and moves them to set the particular setY ot' teeth as YU-NT4., 5t-58 to mosh with each other which will, in accordance with theoriginal design of this jack eil'ect elevating operation. lll/'hen he has reached the elevated position of Fig. 4 and desires to lower, all he has to do -is'to take hold o1 these covers and move them so that the ratchet teeth, which were formerly in mesh, are now out of mesh andthe sots of teeth. as 52-38 and 12-32, which were formerly out of mesh, are now in mesh, whereupon reciprocation of the handle will cause' the block 22 to move continuously downward, regardless of which direction he is swinging the handle.`

Having; thus described my invention, what l claim as new and desire to secure by Letters Patent, is

I. ln mechanism of the class described, in combination with a case and a plurality of telescopiup; screws, means. tor manually rockingr one of said screws on its axis, two sets of ratchet teeth oppositely disposed to each other between one screw and the case, correino fie

he.. mechanism for seiectiveijy' connecthe case to the outer screw, another .cbet mechanism for selectively connecting; .l e enter screw to the inner screw; the ratchet teeth of each of said. ratchet mechenisscs' being reversed with. reference to euch cti or whereby rocking of the inner screw wili canse said screw to be moved continuoneljy in a given direction. with each rockingmovement, and a snppiernentci of ratchet acent to eech of the irst mentioned sets of retchet teeth, each reversed with reierence to the set with which it is `placed., end ont of engagement of the first eet which is in operation, end mechanism for seiectiveljy disengaging each first set ci' retchet teeth and simultaneously engaging each second set of ratchet teeth, the purposes set forth.

3. .in mechanism of the ciess described., two telescopinff screw threaded members, en annular or ratchet teeth on one of seid members, 1L-ratchet riderpl retcteblc with, but reciprocatebly mounted nnen the other telescoping member, a set e n' ict jseeth on seid ratchet rider meshing w a the rst set of ratchet teeth, a second set of chet teeth on the ratchet rider reversed in ciiii-cction to its first set-'of ratchet teeth, and e reciprocetebie member concentric with the first mentioned set of ratchet teeth, and clear of tie saine, carrying a set o* teeth which can with the second set of, teeth on the ratchet rider, mechanism for moving seid reciprocateble member between two diiierent positions in one @if which it holds the itchct rider where the second pair of teeth mesh with each other and the originelle mentioned pair are disengaged end vice versa.

in mechanism of the class described, .two telescoping members, screw threaded with reference to each other, e. 'ratchet rider reciprocetebie with` reference .to the inner member, land non-rotatabie with reference cto, wo circles oi' oppositeljy disposed 4'fteefrfn on said ratchet rider, e set ci i teeth interiittngz; with one ci .i been on the itchet rider cerriedby being in the opposite direction,

the external telescoping member, .and mech einem for selectlvely moving sa1dvrec1proestable member to determincfwhich set of teethon the ratchet rider shall be in operative reletion with its opposing set/of teeth, the purposes described.

o. ln mechanism of the class described,

" two i'zeieecoping members, screw threaded with reiferencc to each other, aV ratchet rider reciprocetable with reference to the inner member, end non-rotatable with reference thereto, two circles o3? oppositely disposed ratchet teeth on said'ratchet rider, a set of ratchet teeth interiittin with one of said sets ci? teethy on the ratcet rider 4carried a part rigid with the external telescoping member, another set of ratchet teeth intertting with the fother set of teeth `on the ratchet rhierl carried by a member, a member so movebie on the external telcscoping inember which is movable llon itndinally of the external telescoping membr and mechanism for selectively moving said reci rocatable member to determine which set o the ratchet rider shall be in operative rela tion with its opposing set of teeth, andy means for detachcbly locking the member 'in each or" its positions.

6. In mechanism of theP class described, a pair'o telescoping screw'threaded members, c ratchet rider siidable lengthwise 4of the internal telescoping member, two concentric rows of oppositely disposed ratchet teethon the ratchet rider, a set of ratchet teeth rigid on the external telescoping member meshing with one set of teethon the. ratchet rider, a member reciprocatabie parallel to the telescoping member having a set of teeth meshin with the other set of teeth on the ratchet ri er, a cover member inciosin'g ythe ratchet rider and attached part, a pin and diagonal siot connection between` said reciprocatable member anda cover member, and a p in circumferential and slot connection between the cover and the exterior telescoping member whereby rotetien oi' the cover member reciprocetes said reciprocetable member a suicient distance to determine which set of teeth on the ratchet rider will be in operative position.

7. In mechanism of the class described, in combination with an external cese', two telescoping screws inside the case, the outer screw engaging the case with threads in one direction and engaging .the inner screw with threads in 'the opposite direction, means for manually rocking the outer screw on its axis in opposite directions, and 'two selectable operating mechanisms, one between the case edliecent screw, the other between the teeth on esA chfa meshanismfs? ba'zwem time 3am and mses.

JHN EUR YELL.

Wimeseg DWIGHT B. CHEMIN@ Amm MGSEN'EHAL 

